Re: [PATCH] writeback: skip balance_dirty_pages() for in-memory fs

Minchan Kim
2010-12-17T15:42:21Z

On Sat, Dec 18, 2010 at 12:34 AM, Minchan Kim <minchan.kim@gmail.com> wrote:
> On Fri, Dec 17, 2010 at 8:21 PM, Wu Fengguang <fengguang.wu@intel.com> wrote:
>> This avoids unnecessary checks and dirty throttling on tmpfs/ramfs.
>>
>> It also prevents
>>
>> [  388.126563] BUG: unable to handle kernel NULL pointer dereference at 0000000000000050
>>
>> in the balance_dirty_pages tracepoint, which will call
>>
>>        dev_name(mapping->backing_dev_info->dev)
>>
>> but shmem_backing_dev_info.dev is NULL.
>>
>> CC: Hugh Dickins <hughd@google.com>
>> Signed-off-by: Wu Fengguang <fengguang.wu@intel.com>
> Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
>
> Is it a material for -stable?

No. balance_dirty_pages tracepoint is new. :)

>
> --
> Kind regards,
> Minchan Kim
>

--
Kind regards,
Minchan Kim